I’m pretty sure it’s average speed= total distance and total time which is A.
F = Magnetic Force
B = Magnetic Field
V = Velocity
*The vectors from the photo you get doing the left-hand rule.
The magnetic force is always perpendicular to the magnetic field.
And as told in the statement, the electron is moving perpendicular to a magnetic field, that is, the Velocity forms an 90 degree angle / Right angle with the magnetic field.
The formula to find the Magnetic Force is:

Where "q" is the Charge and the sin theta is the angle formed by the Velocity and Magnetic Field, in this case it's 90°. Sin 90° = 1.

Newton (N) = C x m/s x T = (C x m x T)/s
Salt water offers the least electrical resistance.
<u>Explanation:</u>
Least electrical resistance indicates that any material which readily allows the electric current through itself, and shows more conductivity.
Here pure water doesn't contain any ions, so it is a bad conductor.
Wood and glass are also bad conductors of electricity.
Salt water contains ions, which conducts electricity which means it shows least electrical resistance.
Answer:
2.80321285141
Explanation:
= Thickness of glass = 4.5 mm
= Thermal conductivity of glass = 0.8 W/mK
= Combined thermal resistance = 
= Thickness of air = 6.6 mm
= Thermal conductivity of air = 0.024 W/mK
The required ratio is the inverse of total thermal resistance

The ratio is 2.80321285141
Answer:
The magnitud of the velocity is

and the direccion:
degrees from the horizontal.
Explanation:
Fist we define our variables:

The letters i and j represent the direction of the movement, i in this case is the horizontal direction, and j is perpendicular to i.
velocities with sub-index 1 are the speeds before the crash, and with sub-index 2 are the velocities after the crash.
Using conservation of momentum:

Clearing for the velocity of the stone after the crash:

Substituting known values:

The magnitud of the velocity is :

and the direction:

this is -28.3 degrees from the +i direction or the horizontal direcction.
Note: i and j can also be seen as x and y axis.